4-(4-Methylphenyl)-2-(prop-2-yn-1-yl)phthalazin-1(2H)-one

In the title compound, C18H14N2O, the dihedral angle between the methylphenyl ring and the phthalazone ring system (r.m.s. deviation = 0.034 à ) is 53.93(9)°. In the crystal, molecules are connected by C - HO hydrogen bonds, forming chains along 101. The chains are linked by �-� interactions centroid-centroid distance 3.6990(12)à , forming layers parallel to (10-1)